Variable tyre pressure wheelset is a mountain biking breakthrough

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Dutch engineers have now developed a digital tyre pressure inflation system. (Photo: Gravaa)
Dutch engineers have now developed a digital tyre pressure inflation system. (Photo: Gravaa)
  • If you always dreamed of digital tyre pressure adjustment on the fly, it is now possible, thanks to Gravaa.
  • Ideal tyre pressure should be adjusted with terrain changes, especially off-road.
  • The Gravaa system inflates and deflates your tyres digitally.


It could reduce the need for plugging annoying slow punctures, as the system balances air loss by reinflating.

Tyre pressure is to cyclists, what spices are to chefs. Too much, or too little, can be the difference between a great ride and awful experience on the bike.

Although most riders will know what their ideal median tyre pressure might be, the truth is that any fixed tyre pressure is always a case of compromise. This is especially true for mountain bikers.

Lower tyre pressures allow superior grip over loose terrain and a less punishing ride over harsh trail sections, featuring many rocks and roots.

If you are trying to roll through a technically challenging rock garden with overinflated tyres, your bike will be difficult to steer and control. By the same logic, an underinflated tyre rolls with greater drag when you want to really put down the leg-power and roll at peak efficiency on a smooth gravel road or tar.

In the ideal cycling world, there would be the choice of variable tyre pressure, adapting to terrain. But that would require dismounting, taking out a handheld pressure gauge and manually adjusting your tyre pressure each time a significant change of terrain is encountered, on your riding route.

The Gravaa system inflates and deflates your tyres
The Gravaa system inflates and deflates your tyres digitally. (Photo: Gravaa)

Selecting a tyre pressure on the go

Some Dutch engineers have now developed a digital tyre pressure inflation system, that could provide a breakthrough for mountain bikers and gravel riders.

Based in Eindhoven, technical specialists at Gravaa, have finalised the prototyping of their adjustable tyre inflation system. It is built into a set of custom hubs and connects a pressure hose to your wheelset’s rims.

What makes this Gravaa system so clever, is that it draws power from the rotational force of your wheels and can be adjusted electronically. Thanks to ANT+ connectivity which has become broadly standardised with most bicycle computer head units and Smartphones, you can simply increase or decrease tyre pressure on the go.

If you always dreamed of digital tyre pressure adj
If you always dreamed of digital tyre pressure adjustment on the fly, it is now possible, thanks to Gravaa. (Photo: Gravaa)

Cost unconfirmed, but you can pre-order

Scaling the high-pressure miniature pump was a huge challenge for Gravaa’s engineers, but they have managed to make it fit in the company’s custom hubs. It uses a clutch unit to convert rotation leverage from the wheels to energy, driving the pump’s electro-pneumatic system, as required.

The potential advantages are enormous, for a rider rolling along on Gravaa’s new mountain bike wheelset. If you suffer a slow puncture, by merely rolling along and powering the system with kinetic energy, it should be capable of keeping your tyres at a constant pressure to get you home comfortably.

With its inflation capable hubs and pressure hose linked rims, riders on the Gravaa wheelset could potentially always be rolling along at the perfect tyre pressure: low for rocky and terrain and loose corners, or firm on those long steady pedalling sections.

Gravaa has not announced what its adaptive inflation mountain bike wheelset will cost, or how much weight the pump system adds. But the Dutch company is accepting pre-orders and if you want the most advanced bit of off-road cycling kit for 2021, this might be it. 

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